Switch



Dec. 6, 1960 R. P. BRIDGES 2,963,551

SWITCH Filed May 26, 1958 3 Sheets-Sheet 1 92 o o FlG. E 87 9 H as Z (\s 11' 1 4 3 allz i I15 0710 1 "Lu .1 LL 5 ,1 I] v 1 W l 29 n+ ii I l I 37 i 0 473 i i l im 57 :1 57 5 15 &5 i 593% 1/ 1f ll,

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R. P. BRIDGES Dec. 6, 1960 SWITCH M4 ml... 7 w H Filed M 26,1958 Fl .8.

R. P. BRIDGES swn'ca Dec. 6, 1960 3 Sheets-Sheet 3 Filed May 26, 1958 United States Patent O swrrcn Ronald P. Bridges, Centralia, Mo., assignor to A. B. Chance Company, 'Centralia, Mo., a corporation of Missouri Filed May 26, 1958, Ser. No. 737,960

6 Claims. (Cl. 200-48) This invention relates to electric switches, and with regard to certain more specific features, to heavy-duty disconnecting switches of the so-called open type operating in unprotected locations.

Among the several objects of the invention may be noted the provision of a rugged open-type electric switch, adapted particularly for high-current values requiring high-pressure, self-cleaning jaw and pivot contacts of permanent high conductivity in all weather and atmospheric environments; the provision of a switch of the class described in which opening and closing operating effort is comparatively small and adapted for manual operation; and the provision of a switch of the class described having improved compensated high-pressure pivot contacts. part apparent and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction and arrangements of parts which will be exemplified in the structures hereinafter described, and the scope of which will be indicated in the following claims.

In the accompanying drawings, in which several of Other objects and features will be in various possible embodiments of the invention are illustrated,

Fig. 1 is a side elevation of the switch shown in closed position;

Fig. 2 is a right-side view of Fig. 1;

Fig. 3 is an enlarged cross section taken on line 3-3 of Fig. 1;

Fig. 4 is an enlarged cross section taken on line 4-4 of Fig. 2;

Fig. 5 is a vertical section through an open upper contact assembly, being taken on line 5-5 of Fig. 6;

Fig. 6 is a jogged section taken on lines 6-6 of Figs. .5 and 8;

Fig. 7 is a horizontal section taken on line 7-7 of Fig. 8;

Fig. 8 is a view similar to Fig. 1, showing the switch in open position;

Figs. 9, 10 and 11 are fragmentary views of the ends of certain of the toggle-acting conducting members of the switch, being shown in sequential operating positions between the open position shown in Fig. 8 and the closed position shown in Fig. l;

Fig. 12 is an enlarged detail section taken on line 12-12 of Fig. 3;

Fig. 13 is an enlarged detail section taken on line 13-13 of Fig. 3; and,

Fig. 14 is an enlarged detail cross section showing certain relationships between a contact button and press-urizing means therefor.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

The switch herein described is adapted primarily for outdoor application to circuits carrying large currents, for example, on the order of several thousand amperes, but is not limited thereto. Such heavy-duty switches require high contact pressures between self-cleaning rubbing contacts, in order to carry the required heavy currents without destroying the contacting surfaces. Such high contact pressures are also dictated by the fact that such switches are often in locations unprotected from corrosive atmosphere, water, ice and the like. Moreover, they may remain closed over long periods without attention, ordinarily tending to bind against opening, by dirt, corrosion and the like. Lastly, the magnetic effects due to heavy current flow through the contact fingers tends to increase contact pressure. Heretofore these conditions required unduly large operating forces which made manual operation of such switches difficult. By means of the present invention, switches of this class are made operable with relatively light forces, so that they may be conveniently manually operated by use of the relatively small forces available from a linemans ordinary operating stick.

Referring now more particularly to Figs. 1-4 of the drawings, there is shown at numeral 1 the usual supporting base for attaching the switch to a pole or the like (not shown). This base carries arms 3, on which are insulators 5, carrying bolting pads 7 to which the moving parts are attached. Bolted to the lower pad 7 (Figs. 2-4) is a lower bracket 9 (see bolts 10). Bracket 9 has side pads 11 to which two heavy copper conductive side plates 15 are rigidly attached by means of bolts 13. These plates extend downward, as shown at 16, to accept between them a U-shaped copper terminal pad 17. The sides 19 of this pad 17 are held by bolts 21. The base 20 connecting the sides 19 is provided with holes 25 for making suitable attachments to the power line, for example through an appropriate bus bar (not shown).

At 27 is shown a heavy-duty switch blade or bar assembly. This is composed of a rigid rectangular (square) tube of copper 29 having a box section, in the lower end of which is inserted and riveted a brace piece 31, including a strut for internally bracing the lower end of the switch blade and to provide reliable pivoting means. Rivets 33 hold the parts 29 and 31 together. Parts 29 and 31 are drilled crosswise to accommodate a pivot bolt 35. Bolt 35 also passes through upward extensions 37 of the side plates 15. These are somewhat resilient, being composed of heavy copper plate. Thus the switch blade 27 may be swung on bolt 35 from the closed position shown in Fig. 1 to the open position shown in Fig. 8.

The open switch position is determined by contact of the front of the switch blade 27 with a forward stop 39 carried on the bracket 9. In order partially to counterbalance the switch blade 27 during opening and closing movements, a spring 41 is anchored at one end to the back of the switch blade, as shown at 43, and at its other end to a fixed crosspin 45 carried between the downward extensions 16 of plates 15. When the switch blade is opened from the closed position shown in Fig.

1 to the position shown in Fig. 8, the spring 41 is nut 55 engages the other cap 49. Each compensator,

piece 47 carries a set of three, preferably equally spaced, round tripod supports 57 having central small raised tips or lugs 59 for conveniently registering with three equally spaced openings 58 in the respective extension 37 of a plate 15. In each opening 58 is press-fitted the stem 60 of a silver contact button 61 having a head 62. The

head 62 of each silver contact button lies between one of the extensions 37 and one side of the switch blade 27. The nut is drawn up a suificient amount substantially to compress the springs 51, which biases together the compensator pieces 47. The tripod supports 57 thus exert local forces against the sides of the extensions 37 in the areas of the silver contacts. This deforms the extensions 37 sufliciently to force the contact heads 62 into strong rubbing engagement with the lower rigid sides of the square'member 29 forming the switch blade 27. The core piece 31 establishes the reactive rigidity of the lower end of member 29. Thus there are provided highpressure wiping pivot contacts for carrying heavy currents and maintaining clean contact surfaces as the switch blade 27 is opened and closed. It will be understood that the raised lugs or tips 59 do not contact with the silver contact button 61 and are for registration with holes 58 to obtain a predetermined alignment of the compensator pieces 47.

Referring now to the upper ends of the square tube 29 (Figs. 2, 7 and 8), it has riveted inside of its upper end a brace piece 63, from which extend lugs 65 supporting a crosspin 67. On pin 67 are pivoted catches 69 and also a pivoted clevis 71. Clevis 71 is formed with an outer eye 73 which is for the reception of the hooked end of a linemans operating stick (not shown). The clevis is provided with stops 75, adapted by engagement with the lugs 65 to limit its rocking movement on the pin 67. Each catch 69 also has lugs 77, providing lostmotion engagement respectively with the sides of the clevis 7'1. Separate springs 79, caught between a lug on the core piece 63 and the respective catch 69, bias the catches respectively toward the upper end of the switch bar 27.

Referring to the upper pad 7 (Figs. 1, 2, 5, 6 and 8), it supports a bracket 81. This bracket 81 extends forward and terminates as an inverted U-shape, having side legs 33, to which are bolted copper plates 85 (see bolts 87). These plates extend upward, as shown at 89, and are connected by bolts 92 to side legs 91 of a U-shaped connector plate 23. The side legs 91 of 23 are connected by a pad 93, in which are four holes 95, adapted to effect attachment with a circuit part such as a bus bar (not shown). At their lower ends, the sides 83 of the U-shape of the bracket 81 are offset, as shown at 97. The plates 85 extend downward adjacent to the otfset portions 97, as shown at 99. These extensions are somewhat resilient. Fitted in between the respective pairs 97, 99 of parts are rotary conductive copper plates 101, backing washers 100 being employed at these points.

Plates 101 are bolted to the sides of a bracket 103 (see bolts 105). The bolts 105 hold in place harddrawn copper spring fingers 107 and back-up leaf springs 109 of beryllium copper. Additional bolts 111, passing freely through holes 113 in the fingers 107, 109 and threaded into the bracket 103, serve for tensioning and adjusting the positions of these fingers 107, 109.

The same type of compensating pressure contact pivot means is used for pivoting the copper plates 101 to bracket 81 and plates 35 as was described in connection with the lower pivot shown in Fig. 3. Like numerals are therefore used for like parts, except that the numerals for the upper compensating pivot means are primed, these being bolt 35', compensating pieces 47, caps 49, springs 51, head 53', nut 55', tripod supports 57, lugs 59', holes 53 and contact buttons 61' including their stems 60 and heads 62'. In this case, the supports 57 and their lugs 59 press inward against the lower extensions 99 of the copper plates 85. This occurs around the openings 58 carrying the pressed-in contact button 61', such as already described. Thus heads 62' of these buttons are pressed into engagement with the outside surface of the pivoted copper plates 101. As regards pivoting, it will be seen that the bolt 35 in this case passes through openings in the stationary members 97, 99, in which the bolt is supported, the pivoted assembly marked 4 129 being. composed of plates 10]. carrying the spring fingers 107, 109 and the bracket 103. It will be understood that the parts of bracket 81 inside of the plates 101 provide a reaction for the inward squeeze of the silver contact buttons 61' on plates 101 under compression from the springs 51.

A pair of tension springs 115 react from a crosspin 117, mounted in the stationary bracket 81, and a crosspin 119 in the pivoted bracket 103 (see Figs. 2 and 5). These springs bias the upper contact assembly 129 outward, as shown in Fig. 8, to a stop position wherein one pair of the flat top ends 121 of the spring fingers 107, 109 engages a flat 123 on the lower margins of the plates 85.

The outer ends of the fingers 107 are curved outward, as shown at 131, and just within these curved portions are provided with silver contact buttons 133 pressed into suitable openings. There is one contact button for each pair of fingers 107 and their backing spring fingers 109. Hereinafter each pair of spring fingers 107, including their backing fingers 109, will be separately referred to as pairs A, B and C of spring finger contacts.

The bracket 103 serves an additional purpose, being formed with an extension 125, at the end of which are mounted two rollers 127. These are adapted to be engaged by the upper moving end of the switch blade 27 as the switch is closed (compare Figs. 8, 9, 10 and 11). The complete rotatable contact assembly 129 therefore comprises the pivoted plates 101 with attached spring fingers 107', 109 and the attached bracket 103, including its extension 125 and rollers 127. In some cases the rollers 127 may be omitted.

Operation is as follows, starting with the open position of the switch shown in Fig. 8:

The knob of a linemans stick is inserted into the eye 73 and pushed upward. The upper stops 75 of the clevis 71 engage lugs on blade 27, whereupon the blade rotates (anticlockwise in the drawings), until the upper, inner fiat sides of the blade 27 engage the rollers 127 (Fig. 9). When this occurs, the upper contact assembly 129 is driven clockwise, the switch blade moving anticlockwise. Shortly after this clockwise motion starts, the upper sides of the switch blade 27 are engaged by one and only one pair of contact buttons 133 of a spring finger assembly marked A. Bevels 137 and the upper side margins of tube 29 allow the buttons 133' to be cammed up onto the side surfaces of 29. Thus the reactive force of one pair and only one pair of fingers needs to be sprung to receive the switch blade. As the motion proceeds, one and only one additional pair of contact buttons 133 of the second set of contact fingers marked B needs to be sprung into engagement (Fig. 10). As the motion proceeds farther, the last pair of silver contact buttons 133, of the set of fingers marked C, is swung apart by entry therebetween of the upper sides of the switch blade. This individualization of the wedging action of entry of the upper end of the switch blade 27 in regard to the successive pairs of spring fingers A, B and C favors a gradual and easy closing action in passing through the configurations shown in Figs. 9, l0 and 11.

As the motion proceeds, it follows of course that the sprung-apart pairs of contact buttons 133 of sets A, B and C have sliding actions on the opposite sides of the switch blade, which produces a resistance against closing movement. However, this resistance is very easily overcome for the reason that as the switch blade assembly 27 and the swinging assembly 139 swing toward closed position (Fig. 1) they approach a straight-line relationship as they advance (Figs. 9-11). The result is in the nature of a toggle action, that is, assemblies 27 and 129 have an increasing mechanical advantage against such resistance as results from rubbing of the buttons 133 on the opposite sides of assembly 27. The resistances to be overcome are forces tangent to the trajectories of butaseauei tons 133 on the sides of tube 29. These trajectories on 29 are shown by dotted darts T in Fig. 11. Finally, when the assemblies 27 and 129 are straight, as shown in Fig. l, the catches 69 ride over lugs 135 on the bracket 81, to form a holding latch. The required movement is permitted by the lost motion between catches 69 and clevis 71 and by the holding springs 79.

In order to reopen the switch, the linemans stick is .pulled down in the eye 73. The first rocks the clevis,

which in turn rocks up the catches 69, whereupon the assembly 27 may be pulled down clockwise to the stop 39 (Fig. 8). The contact assembly 129 follows anticlockwise under action of springs 115, until the angled position against stops 123 is reached.

Again regarding the toggle action above referred to, it will be seen that it is useful not only in advantageously overcoming the reaction from rubbing of the silver contact buttons 133, but also in overcoming the rubbing reaction of both sets of silver contact buttons 61 grouped around the pivot bolts 35 and 35' under their pressures from the springs 51, 51'.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. An electric switch comprising first and second stationary conductive line terminals, a conductive switch blade having one end pivoted for rotation to one of said terminals and having substantially flat sides parallel to the plane of rotation, a conductive contact assembly pivoted for rotation on the second terminal, said contact assembly comprising an arm and a plurality of pairs of spring contact fingers arranged in opposed coplanar rows movable in planes parallel to the plane of rotation of the blade, means biasing said contact assembly to an angled switch-open position of said fingers, an arm on said contact assembly adapted to be engaged by the unpivoted end of the switch blade when the latter rotates to switch-closed position, whereby the contact assembly is driven to rotate into switch-closed position wherein said spring fingers engage the sides of the blade, said switch. blade being constituted by a hollow rectangular box section containing in each end an internally supporting core piece, the core piece in the pivoted end of the switch arm forming a pivot bearing and a core piece in the other end of the switch blade supporting a catch mechanism, each pivot means for the switch blade and the contact assembly being constituted by a headed bolt having a threaded nut, said bolt passing through stationary line terminal parts flanking the respective pivoted member said parts being adapted to flex, conductive contact buttons in the respective flanking parts adapted slidingly to engage the pivoted members respectively as they rotate, slidable pressure members on the respective bolts outside said flexible flanking parts adapted to engage the latter, caps adjacent the respective bolt heads and nuts, and springs between each pressure member and adjacent cap adapted to press each compensating pressure member against the adjacent flexible parts in the regions of said contact buttons.

2. An electric switch according to claim 1, wherein the number of contact buttons in each flexible part around a respective bolt is at least two, and wherein each pressure member has portions engageable with the stationary member adjacent the respective ones of each of the set of buttons.

3. An electric switch according to claim 1, wherein the number of contact buttons in each flexible part around a respective bolt is three, and wherein each pressure member has tripod portions engageable with the stationary member adjacent the respective ones of each of the set of three buttons.

4. Conductive pivot means for a conductive switch member adapted to be pivoted between spaced flanking parts of a conductive stationary element, comprising flexible portions in said flanking parts, a bolt passing through said pivoted switch member and said flanking flexible parts, groups of contact buttons arranged around the bolt in said flanking parts and having heads engaging the pivoted switch member, compensating members on the bolt outside of said flanking parts respectively and having supporting pads engageable with the flanking parts adjacent said buttons respectively, said bolt having a head on one end and a threaded nut on the other, caps under said head and nut respectively, and springs between the respective compensating members and caps adapted to drive said compensating members into localized pressure engagement with said flexible parts and the buttons carried thereby, so as to spring said buttons against the pivoted switch member therebetween.

5. Conductive pivot means for a conductive switch member according to claim 4, said pivoted switch member comprising a tubular box section of conducting material and a core piece therein surrounding said bolt and adapted to brace said tubular section against thrust from said contact buttons.

6. Conductive pivot means for a conductive switch member adapted to be pivoted between spaced flexible parts of a conductive stationary element, a pivot member passing through said pivoted switch member and said flexible pants, groups of contact buttons arranged adjacent the pivot member in said flexible parts and having heads engaging the pivoted switch member, compensating members on the pivoted member outside of said flexible parts respectively and having supporting means engageable With the flexible parts adjacent said buttons respectively, said pivot member having head means on opposite ends, caps under said head means respectively, and springs between the respective compensating members and caps adapted to drive said compensating members into localized pressure engagement with said flexible parts and the buttons carried thereby, so as to spring said buttons against the pivoted switch member therebetween.

References Cited in the file of this patent UNITED STATES PATENTS 1,967,623 Massey July 24, 1934 2,174,237 Crabbs Sept. 26, 1939 2,227,925 Cornell et al. Jan. 7, 1941 2,780,684 Brown et al. Feb. 5, 1957 UNITED STATES PATENT OFFICE CERTIFICATION OF CORRECTION Patent No, 2 963 561. December 6, 1960 Ronald P. Bridges It is hereby certified that error appears in the above numbered pate ent requiring correction and that the said Letters Patent should read as corrected below.

Column 4 line 38, after "lugs" insert 65 line 68, for "139" read 129 column 5, line 57, after "member" insert a' comma.

Signed and sealed this 9th day of May 1961..

(SEAL) Attest:

ERNEST W, SWIDER Attesting Officer DAVID L.- LADD Commissioner of Patents 

